- Explore the effects of long-term tDCS on intrinsic connectivity between pain processing and modulatory regions and other brain networks (e.g. default mode network, sensory motor network) in FM. Our preliminary data suggest that FM patients display enhanced connectivity between various pain processing regions and the default mode network, a specific brain network that is active during periods of inactivity. We propose that tDCS will decrease connectivity between pain modulatory regions and other networks such as the default mode network thus resulting in a reduction in pain symptoms.